Ni(II)-Directed Supramolecular Metallogel: Stimuli Responsiveness and Semiconducting Device Fabrication

Metal-organic gels (MOGs) are a type of supramolecular complex that have become highly intriguing due to their synergistic combination of inorganic and organic elements. We report the synthesis and characterization of a Ni-directed supramolecular gel using chiral amino acid L-DOPA (3,4-dihydroxy phenylalanine) containing ligand, which coordinates with Ni(II) to form metal-organic gels with exceptional properties. The functional Ni(II)-gel was synthesized by heating nickel(II) acetate hexahydrate and the L-DOPA containing ligand in DMSO at 70 °C. The rheological tests have verified the gel with its mechanical stability, while a SEM image has shown a spherical aggregate morphology. The gel is photo-responsive in nature and exhibits gel to sol transformation upon adsorption of toxic gases like NH₃ or H₂S. Notably, electrical conductivity of the gel was observed in electronic metal-semiconductor (MS) junctions' devices with a measured conductivity of 0.9×10^-6 Sm^-1. These devices also exhibited Schottky barrier diode characteristics, underscoring the multifunctional potential of the Ni(II)-gel.